Indicator snap gauge



INDICATOR' SNAP GAUGE Filed UC'.

l Inventor Patented Jan. 3, 1933 NTD TATES @PATENT OFFICE ICTOR SNAPGAUGE Application filed October 1, 1931.l Serial No. 568,340.

rlhe primary object of the invention resides in Aan instrument which maybe set to accurately check the correct size of a piece of work and whichwill indicate the amount of any variance in the size, thatis, if thepiece ofA work is oversized or undersized.

Another object of the invention is to provide a snap gauge in which theaccuracy of the work 1s assured; loss of time in setting m gauges by aninspector is eliminated; and the human e ment usually dependent in theuse of the conventional form of gauge is abolished. A `further object ofthe invention is th 35 provision of an indicator snap gauge which is"simple of construction, inexpensive of manufacture, easy to handle whenin use, and strong and durable for the purpose intended.

With these and other objects in view, the

2@ invention resides in the certain novel construction, combination andarrangement of parts, the essential Jfeatures of which are hereinafterfully described, are particularly pointed out in the appended claim, andare 25 illustrated in the accompanying drawing, in

which:

Figure 1 is a front elevational view of my improved snap gauge showingarts in section, the dotted line on'the indlcator gauge 3@ showing theposition of the same when the work is oversized.

Figure 2 is a perspective view of the snap gau e.

Figure 3 is a horizontal sectional view on 35 the-line 3--3 of Fig. 1,and

Figure 4 is a perspective view of the sev- 45 trally with a hand gripopening 12. The terminal ends of the yoke frame 11 are pro-v vided Withaxially alined tubular housing 13 and 14, the outer end of the housing13 being screw threaded to receive the threaded nipple 1 5 o f astandard indicator 16, and which indicator includes an actuating rod 17slidable through the nip le 15 and which also extends into the bore ofpthe housing 13. The standard indicator 16 includes an indicating hand 18and a dial 19 which is graduated to indicate ten-thousandths of an inch.The indicator 16 is xedly secured to the tubular housing 13 by a locknut 2O which is threaded to thenipp e 15 and is screwed tight againstthe outer end of the housing 13.

Slidably mounted in the enlarged bore 21 of the housing 13 is a slidableanvil 22, the outer extending end of which is provided with an enlargedhead 23, While the inner end of the anvil is reduced in diameter toprovide a shoulder 24 and a reduced tubular extension 25. The extension25 is provided with a recess 26 opening through the inner end thereofand which receives the free end of the actuating rod 17. A. coil spring27 surrounds the tubular extension 25 and has one end seated against theshoulder 24 and its opposite end seated against the shoulder 28 formedin the housing 13. '.ll'iis spring tends to normally extend the headedend of the anvil outwardly beyond the inner end of the housing 13, andfor limiting the sliding movement of the anvil in opposite directions, Iprovide a slot 29 in one side of the anvil and extend a stop pin 30transversely through the housing 13 and slot 29. it will therefore beseen that this slot permits of a limited slidin g movement of the anvilin opposite directions.

Extending into the inner end of the housing 14 is an adjustable anvil31, the outer end of which is provided with an enlarged head 32, whilethe inner end of the anvil 31 terminates in a tapered or conical portion32, while formed in this end of the anvil is a threaded bore 33.y Oneside of the anvil 31 is slotted or notched as at 34 and passingtransversely through the housing 14 is a stop pin 35 which also passesthrough the slot 34. This pin and slot connection serves to limit theadjustmentl of the anvil 31 in opposite directions.

The outer end of the bore formed in the housing 14 is screw threaded vasat 36 for threadedly receiving an adjusting screw 37, the said screwbeing provided with an extension portion 38 which isprovided withoppositely disposed slots.39 which slots open onto the outer end of theextension portion 38. The portion 38 of the adjusting .screw is providedwith a conical seat 40 which opens through the opposite end o the screwand which end is provided with an enlarged recess 41. Extending througha passage in the adjusting screw 37- is a lock screw 42, the shank ofwhich is threaded into thevthreaded bore 33 provided inthe inner end oftheanvil 31, while the head 43 of the screw is adapted to engage ashoulder 44 formed within the adjusting screw 37. It will therefore beseen that when the locking screw 42 is screwed into the recess 33, theinner end of the anvil 31 will be drawn down upon the conical seat 40which in turn will set up a wedging action to expand the resilient wallof the adjusting screw against the walls of the bore formed in the.housing 14. By loosening the screw 42 and turning the adjusting screw37, the anvil 31 `may beset to the desired adjustment within the limitsof its sliding movement, and after being moved to the desired positionthe '25 lock screw 42 is again screwed home in order to set up theclamping action between the split or slotted end of the locking screwand the wall ofthe bore in the housing 14.l

In practice, the instrument is set for the checking of a piece of workof a desired size, but before setting the instrument, the piece of workis checked with a micrometer or' master set block in order that the sizeof the Work may be'correctly obtained. In Figure 1 of \.the drawing Ihave shown a shaft A of the size to be checked and the snap gauge isadjusted accordingly, .that is, the anvil 31 is moved to the adjustmentdesired. When so adjusted, the indicating hand 18 of the 40 standardindicator may normally indicate a negative amount as shown in Figure 2of the drawing, but when the gauge is snapped onto the work A, the anvil22 will be moved inwardly and during such movement the same actuates theactuating vrod 17 whereupon the hand 18 moves to the zero mark on thedial. For the purpose ot guiding-the anvil to posi- Vtion with respectto the work, I bevel the front and back ot the heads 23 and 32 as at 45.The

beveled surfaces act as guides for applying the gauge tothe work A. Inthe event that the work A should be oversized, the hand 18 will move toa position beyond the zero mark o r as shown in dotted lines in Figure1, where- 5.5 upon it is readily understood thatthe size of the workdoes not measure up to the specification. .On the other hand if the workis -undersized, it will also show on the standard indicator as theindicating hand 18 will be short .60 of the zero mark, whereupon it'isreadily understood 'that the work is not in accordance with' thespecifications.

From the foregoing description, it will be seen that I have provided anindicator snap gauge' which is accurate in use, which is not affected byexpansion and contraction due to the heat from the hand of the user, andwhich is .a cominon annoyance in gauges now in use which affect theaccuracy of the same. Furthermore, the device is constructed towithstand shocks to which instruments of this kind are sub' cted duringhandling and in the event that t e standard indicator 16 should becomeout of adjustment, it may be reset. In the presentlinstance, I haveshown that type of standard indicator 16 in which the hand may beadjusted by the turning of the outer ring 46. Although this one type of'standard indicator has been illustrated 1n the drawing, it will beunderstood that various other types may be substituted therefor ifdesired. It will also be appreciated that although one instrument may beconstructed to measure sizes within a certain range, other sizeindicators may be constructed to measure within4 other ranges.

While Ifhave shown and described what I i deem to be the most desirableembodiment of my invention, IJwish it to be understood thatf variouschanges that come within the scope o the appended claim may be resortedto ifudev sired.

Ha-ving thus described the invention, what I claim as new and desire tosecure by Letters Patent is An indicating instrument comprising a yokeframe having axially alined tubular housings at the ends thereof, anindicating mechanism mounted on said frame and having an actuating rodextending into one of said housings, a slidable anvil mounted in thehousing and engageable with said actuating rod upon inward movementthereof, spring.

means acting upon'said slidable anvil to normally move the same toanextended position, and a stationary anvil mounted in the.

other of said housings, and means for ixedly adjusting said stationaryanvil relative to said slidable anvilsaid means including an adjustablescrew threaded into said last mentioned housing and having expansiblewalls, a conicalseat in said .adjusting screw, the inner end of saidstationary anvil being tapered and engagmg said seat, and means forforcing and securing the tapered end upon said seat to cause a wed 'ngaction therebetween to expand the expanslble walls ofsaid screw intoengagement with the inner walls of said housing.

In testimony whereof I atx my signature.

- JOHN N. SCHNEIDER.

